JB Systems D2 Series Operation Manual page 4

ENGLISH
 When installed in a booth or flight case, please make sure to have good ventilation to improve heat
evacuation of the unit.
 To avoid condensation to be formed inside, allow the unit to adapt to the surrounding temperatures when
bringing it into a warm room after transport. Condense sometimes prevents the unit from working at full
performance.
CLEANING THE UNIT:
Clean by wiping with a cloth slightly dipped with water. Avoid getting water inside the unit.
Do not use volatile liquids such as benzene or thinner which will damage the unit.
Clean the ventilation holes regularly with a vacuum cleaner. This increases the cooling capacity of the
amplifier fans and helps preventing temperature overheat.
CONNECTIONS
Be sure to turn off the unit before you make changes to the wiring. For the signal inputs we recommend
using the XLR-connections. Use good quality signal cables to ensure excellent audio quality. For the
®
speakers you must use the Speakon outputs. In the description of the unit you will find more information on
how to connect the amplifier.
FUNCTIONS
1. VENTILLATION HOLES: during its operation the amplifier produces heat that needs to be dissipated.
The fans inside the amplifier must be able to evacuate the heat in the most effective way. Therefore is it
very important not to cover any of the ventilation openings as this may result in overheating. Clean the
ventilation holes regularly with a vacuum cleaner. This increases the cooling capacity of the amplifier
fans and helps preventing temperature overheat.
2. GAIN CONTROLS: These potentiometers are used to control the input sensitivity of the amplifier. Each
channel has its own control.
You can use these controls to set the maximum sound level of your setup:
 Turn both controls on the amplifier to the left.
 Put on some music on and make sure the VU meters on your mixer are at 0dB. (from time to time
the red zone is lit)
 Set the Master output from your mixer to maximum.
 Open the Gain controls from the amplifier until the maximum desired sound level is reached.
 Make sure nobody can reach the Gain controls of the amplifier.
You have just set the maximum level the DJ is able to produce. Your neighbors will be glad... (in some
cases the DJ is not )
Note: In Bridge mode, only the gain control of the left channel is used to adjust the input sensitivity.
3. SIGNAL LEDS: these LEDs indicate that a music signal is present at the inputs.
4. CLIP LEDS: Turn on just before the maximum, distortion free, output level of the amplifier. They indicate
that the internal limiter starts working. The clip LEDs may turn on shortly from time to time but they may
certainly not turn on for longer periods. In this case you have to turn the output level down!
5. OPERATION MODE LEDS: These LEDs indicates the operation mode. Switch (13) on the rear panel is
used to choose one of the 3 possible modes:
 STEREO MODE: This is the most common mode, both channels are working separately.
JB SYSTEMS
®
OPERATION MANUAL
3/42 D2-900 ~ D2-1200 ~ D2-1500
ENGLISH
 MONO MODE: Both LEDs (5) are lit. Basically this is identical to stereo mode but the inputs of
both channels are linked so the output will be mono. In this case you only need to use the input of
the left channel to drive both output channels.
 BRIDGE MODE: Both channels are linked in "bridge mode" to obtain a mono output with much
higher power.
6. PROTECT LEDS: The protection LED is on when the speakers are disconnected from the amplifier. This
occurs in the following situations:
 During the first seconds after switching on the amplifier.
 When the temperature of the power stage becomes too high.
 In case of a technical defect: DC protection!
 While switching the amplifier off, the "protect led" turns on for a short time.
7. HP FILTER LED: Indicates that the high pass filter (HPF) is switched on for this channel (left and right
channels have their own HPF LED) Please refer to numbers 18 and 20 to learn more about this filter.
8. LP FILTER LED: Indicates that the low pass filter (LPF) is switched on for this channel (left and right
channels have their own LPF LED) Please refer to numbers 18 and 20 to learn more about this filter.
9. MAINS SWITCH: Used to turn the amplifier on and off. A few seconds after switching on the amplifier it
is ready for operation. The blue led is on when you turn the amplifier on.
10. FAN & VENTILLATION HOLES: during its operation the amplifier produces heat that must be
dissipated. The fans inside the amplifier must be able to evacuate the heat in the most effective way.
Therefore is it very important not to cover any of the ventilation openings as this may result in
overheating.
11. XLR inputs: You can connect these balanced inputs to balanced and unbalanced line level audio
sources:
 Balanced source: Use good quality XLR/XLR balanced audio cables.
Wiring of the XLR connector:
PIN1: GND PIN2: pos+ PIN3: neg-.
 Unbalanced source: Use good quality XLR/cinch audio cables.
Wiring of the XLR connector:
PIN1: GND PIN2: pos+ PIN3: GND (connect to PIN1)
12. XLR LINK outputs: in several cases you need a lot of power that can't be produced by only 1 amplifier.
In these cases the link outputs are used to daisy chain the inputs/outputs of several amplifiers. The
wiring if these male XLR outputs are identical to the inputs.
13. OPERATION MODE switch: Used to set the operation mode of the amplifier. The most common
operation mode is "stereo". If you need more power, you can operate the amplifier in bridge mode. Refer
also to point 5 for more information.
14. LIMITER switch: This amplifier has built-in limiters to protect both the amplifier and the connected
speakers. We strongly suggest to put this switch in on position at all times. Nevertheless if you are
experienced or you use an external limiter you can switch the internal limiters off.
15. L+R SPEAKON OUTPUTS: use these Speakon
or mono mode. Wiring of these connectors is as follows:
 POS(+) = Speakon ®
connector PIN1+ and PIN2+
 NEG(-) = Speakon ®
connector PIN1- and PIN2-
JB SYSTEMS
®
OPERATION MANUAL
®
connectors to connect your speaker cabinets in stereo
4/42 D2-900 ~ D2-1200 ~ D2-1500